Signal system.



J. J. RUDD-ICK. SIGNAL SYSTEM.

APPLIOATION FILED nu 2a, 190s.v

903.785. Patented Nov. 10,1908.

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SIGNAL SYSTEM. AlPLIoATIoN FILED nu 23, 190s.

Patented Nov. 10, 1908.

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SIGNAL SYSTEM.

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J. J. RUDDICK. SIGNAL SYSTEM. APPLIMTION FILED MAY 23,-1908.

903,785. PatenteaNov. 1o, 1908. 9 SHEETS-SHEET B.

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/Wbessesa k() I J. J. RUDDICK. SIGNAL SYSTEM. APPLICATION FILED MAY z3,1908y Patented Nov. 10, 1908. r 9 SHEETS-SHEET S.

N o D m f I NW j 1 `UNITED STATES "PATENT OFFICE.

JOHN J. RUDDIGK, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO UNITED STATESELECTRIC SIGNAL COMPANY, OF PORTLAND, MAINE.

SIGNAL SYSTEM.

To all whom it may concern:

Be it known that I, JOI-IN J. RUDDICK, a citizen of the United States,residing at Newton, county of Middlesex, and State of Massachusetts,have invented an Improvement in Signal Systems, of which the followingdescription, in connection with the accompanying drawing, is aspecification, like letters on the drawing representing like parts.

This invention relates to electric block signal systems which areespecially adapted for use in connection with railways for indicating toa train or car whether or not the block ahead is free or occupied.

The invention has been herein shown as applied to an electric railway,but it is equally applicable to steam railways.

The principal object of the invention is to provide a signaling systemwhich will not be liable to be disabled by lightning, crossed wires, orsimilar causes. In order to secure this end I have provided a signalsystem in which the wire or wires which connect the two signal boxes atopposite ends of a block are normally disconnected from the ground sothat under normal conditions there is no ground connection at either boxwhich could afford a possible path for a lightning charge. The result isthat a stroke of lightning will select some object such as a tree whichaffords a better path to earth than the wire or wires connecting thesignal boxes and forming part of the signaling circuit.

In the preferred form of my invention there are two wires extending thelength of the block and connecting the boxes at opposite ends thereof.One of these wires constitutes part of the signal circuit and the otherconstitutes part of the signal-restoring circuit. Under normalconditions when the signals on the block are set at safety, the twowires are electrically connected at each end and are each disconnectedfrom both the feed and the ground, whereby a closed me accidentalcrossing of the two wires, I place the signal in a signal-containingcircuit Specification of Letters Patent.

Application led May 23, 1908.

Patented Nov. 10, 1908.

Serial No. 434,666.

which is normally disconnected from said closed loop so that even if thewires of the loop become crossed the circuit containing the signal isnot affected.

In the embodiment of the invention herein illustrated the signal is setat danger by opening the normally closed loop or circuit and connectingit at one place with the feed and at another place with the ground andalso connecting it with the signal whereby a complete circuit isestablished from the feed to the ground which includes the signal. Thisis preferably done automatically by the car or train as it enters ablock. The signal is restored to safety by disconnecting the loop fromthe feed and from the ground and again closing said loop. y

In the drawings wherein I have illustrated one embodiment of myinvention, Figure I is a diagrammatic view showing a block of a railwaytrack with a signal box at each end. thereof, the parts being shown insaid view in their normal condition; Fig. 2 is a simplified diagrammaticview of the closed metallic circuit connecting the two signal boxes atopposite ends of the blocks; Fig. 3 is a diagrammatic view showing theboxes at the adjacent ends of two adjacent blocks; Fig. 4l is adiagrammatic view of the box at the entering end of the block showingthe circuit which is first made when the car enters the block; Fig. 5 isa diagrammatic view of the two boxes at opposite ends'of the blockshowing the second path of the circuit during the setting operation ofthe signal; Fig. 6 is a simplified diagrammatic View of the circuitshown in Fig. 5; Fig. 7 is a diagrammatic View of the boxes showing thecircuits when the signals have been set by a car entering the block;Fig. 8 is a simplified diagrammatic view of the circuit shown in Fig. 7Fig. 9 is a diagrammatic view of the signal box at the exit end of theblock showing the first course of the circuits; Fig. 10 is adiagrammatic view of the same box showing the course of the restoringcircuit; Fig. Il is a plan View of the magnets and their armatureslocated in either of the boxes; Fig. l2 is a section on substantiallythe line -w, Fig. Il, looking toward the top of the sheet; Fig. 13 is aview on the same line m-m, looking toward the bottom of the sheet; Fig.11i is a section on the line g/-i Fig. Il; Fig. l5 is a detail of thearmatures for the magnets (Z, c and f.

In the drawings I have shown the block IIO on the track which isprotected by the signal I as including a space of single track betweenthe two turn-outs 3 and 3a. The signal system includes a signal box ateach end of the' block, said signal boxes being designated generally byA and B. Under normal couditions the two signal boxes are connected in aclosedmetallic circuit or loop, as shown in the simplified diagrammaticview in Fig. 2, said circuit comprising the two wires 4 and 5 (4 being asignal circuit wire and 5 being a signal-restoring circuit wire) whichare disconnected from the feed wire 6 or other source of electricity,and also from the ground or return circuit which may be the rails 7 ofthe track. lVhen the car enters the block at signal box A the closedloopv is opened at signal box A and connection is made at the open endsthereof with both the feed and the ground whereby a signal-settingcircuit is established such as shown in the simplified diagrammatic Viewin Fig. 6, and which extends from the feed 6v to the signal box A,thence through wire 4 to the signal box B, thence back to signal box Athrough wire 5 and thence to the ground.. In traversing this circuit thecurrent passes through both signal boxes and thus operates to set thesignal at each end of the block. After the signals have been set thissignalsetting circuit is discontinued and a signal circuit formaintaining the signals in operation is established, such as shown inthe simplified diagrammatic view Fig. 8, the current being taken fromthe feed G to signal box A, from the latter through the signal wire 4 tosignal box B and thence to the ground or return wire 7. lvhen the carpasses out from the block the sigi'ial is restored by establishing asignal-restoring circuit through both signal boxes by means of thesignal-restoring wire 5. These results are secured in the presentembodiment by a signal box mechanism which comprises two signal-settingmagnets a, b, a lock-releasing magnet c, a signal-restoring magnet j',and two currentdirecting magnets al and c. These magnets mayconveniently be arranged in the manner shown best perhaps in Figs. 11to- 15, although a similar arrangement is shown diagrammatically in theother figures of the drawings.

The signal-setting magnets a and Z) have situated between them aswinging armature 9 which is adapted to be attracted toward the poles 10of either magnet as it is energized. rThis swinging armature is mountedon a suitably-journaled rock-shaft 11 and it carries a head 12 ofinsulating material carrying the two pairs of insulated contacts 13, i4and 15, 16.

17, 18 are a pair of insulated contacts which are adapted to be bridgedby the contact 13- when the armature 9 is attracted byy the energizedmagnet b, and 19, 20 are a similar pair of contacts adapted to be Ibridged by the contact 15 when the armature 9 is thus attracted.

21, 22 and 23, 24 are two pairs of' insulated contacts adapted to bebridged by the contacts 14 and 16 respectively when the i armature isattracted by the energized magnet a. l

The armature 9 is normally held 1n its 'neutral position between the twomagnets,

as. shown in Fig. 11, by a retaining device herein shown as an arm 26pivoted at 27 tok a suitable support and having a roll or projection 28which engages in a V-shaped recess 29 formed in an arm 30 rigid with therock-shaft 11. r1`he arm 26 carries at its end a contact 31 which issuitably insulated from the arm, as at 32, said contact 31 normallybridging two suitably-supported insulated contacts 33, 34. Then thearmature 9 is swung in either direction by either of the magnets a, thesides of the V-shaped notch 29 by acting' on the roll 28 force theretaining device 26 backwardly thereby disengaging the contact 31 fromthe contacts 33, 34.

The rock-shaft 11 has rigid therewith an arm 35 which coperates with alock 36 to lock said rock-shaft in the position it assumes whenattracted by either of the magnets a or Z). lVliile this lock may haveany suitable construction l have hereinv shown it as comprising a head37 carried by the arm 35 and against which rests the locking projection36', the latter being sustained by an arm 38 suitably pivoted at 39.Vhen the armature 9 is attracted by either of the magnets a or b, theturning of the rock-shaft 11 carries the head 37 beyond the projection36 thereby allowing said projection' to drop Adown back of the end ofthe head and preventing the shaft 11 from returning to its normalposition. The arm 38 may be acted on by a suitable spring which willnormally tend to force it into this locking position, or the signal boxmay be soV placed that the arm will be thrown into this locking positionby gravity. Said arm has a portion c thereof which acts as an armaturefor the lock-releasing magnet c.

The magnets d, e and f each have swing,- ing armatures designated,respectively, el', e', f. These armatures are independently pivoted inlsuitable bearings as at 46, as shown best in Figs. 13 and 15. The arma:-ture Z carries two contacts 47 and 48 which are insulated from eachyother, the contact 47 being adapted to engage two insulated contacts 49and 50 when the armature is attracted by the magnet (Z, and the contact48 being adapted to bridge two insulated contacts 51 and 52 when thearmature is in its normal position, as shown in F ig. 11. The armature ehas connected therewith an insulated contact 53 adapted to bridge twoinsulated contacts 54 and 55 when the armature is attracted by themagnet e, and the armature f has associated therewith'an insulatedcontact 56 adapted to bridge two insulated contacts 57, 58 when thearmature is in its normal neutral position. The armatures d and c areprovided with means so that whenever either is attracted by its mag netthe other is locked against movement, this being convenientlyaccomplished by providing each armature with the lateral projection 60which coperates with a locking nose 61 carried by a rock-shaft 62.

The rock-shaft has extending therefrom two arms 63, each of which isadapted to be engaged by a pin 64 extending from the armature.

The locking projections 61 have such a shape relative to the noses ofthe projections 60 that when either armature is attracted towards itsmagnet the rock-shaft will be turned by engagement of one of the pins64k with the arm 63 thereby swinging one of the projections 61 down infront of the nose of the magnet which remains in neutral position, saidnoses being so shaped that when either armature is attracted thecorresponding nose will pass under the projection 61 before it strikesthe arm 63.

I have above briefly described the mechanical construction of thearmatures and the magnets of each signal box, and I will now describethe manner of wiring each box, and since the manner of wiring the twoboxes at each end of the block is alike, a description of one willsuffice for both.

The feed wire 6 or other source of electricity is connected by a wire70, which preferably connects with a white signal lamp 71, and a wire 72with the coils of the signalsetting magnet a. ll-he coils of said magnetare connected by a wire 7 3 with the contact 21. Said contact 21 isconnected by a wire 7a which preferably has suitable resistance 75therein with the coils of the magnet cl, and said magnet Z is connectedby a wire 76 to a suitable track switch 77 adapted to be operated toclose the circuit by the car passing over the track and which is hereinshown as arranged to connect the wire 76 with the ground or return wire.The wire 76 is also connected by a wire 78 with the coils of the magnete, and said magnet is connected by a wire 79 with another track switch80. 'The two magnets CZ and e and their circuits are merely for thepurpose of properly directing the current when the car enters or leavesthe block, all as will be more fully described, and are necessarybecause the connection with the ground is established by means of trackswitches which are operated by the wheels of cars passing over thetrack. If the circuits were `closed by trolley switches, that is,switches adapted to be closed by the trolley the two magnets as hereinshown would not be necessary because the current would be given itsproper direction by the trolley switch. These track switches may haveany suit-able construction. in my co-pending application Serial No. L534,665 filed May 28, 1908, 1 have shown a track switch suitable for usein the device herein illustrated.

. The contact 22 is connected by a wire 81 with the contact 57, and thecontact 58 is connected to the signal wire t. The signalrestoring wire 5is connected to each of the contacts 51, 49 and 5-1. The contact 52 isconnected by wire 82 to the coils of the lockreleasing magnet c and thecoils of said magnet are connected by wires 83 and 84- to the twocontacts 19 and 23. The contacts 2O and 2st are connected by wires 85 tothe wire 72. The coils of the lock-releasing magnet are also connectedby wires 88 and 86 with the contact 83 and the contact Se is connectedby a wire 87 0 with the coils of the setting magnet rlhe other end ofthe coil of setting magnet 5 is connected by a wire 87 with the wire 81and said magnet is also connected by the wire 88 with the contact 17.rlhe contact 18 is connected by a wire 89 to the return circuit 7 andsaid wire 89 has a red signal light 90 therein. The wire 89 is alsoconnected by a wire 91 with the contact 50. The wires 89 and 70constitute what l have called the signal containing circuits.

As stated above, under normal conditions the two signal boxes A and Bare connected by a metallic circuit and are disconnected both from theground and from the feed wire 6, as shown both in the simplified diagram Fig. 2 and in the complete diagram F ig. 1. In Fig. 1 the heavyline indicates this closed metallic circuit which is formed by thecontacts when the armatures are in their neutral position. This circuitincludes the signal-restoring wire et, contacts 58, 56, 57, wire 81, 87,coils of signal-setting magnet wire 870, contacts 34e, 31, 33, wire 86,coils of the lock-releasing magnet c, wire 82, contacts 52, 48, 51, andsignal wire 5, and thence through the other box in exactly the same wayexcept reversed, as clearly shown in F ig. 1.

Then a car enters the block a preliminary signal-setting circuit isestablished through signal-box A in the manner shown in heavy lines inFig. i by the closing of the switch 77, for as soon as said switch isclosed, 'there is a clear circuit from the feed 6 through wire 70, 72,signal-setting magnet c, wire 73, contact 21, wire 7l, magnet Z and wire76, as shown in heavy lines in Fig. el. This results in opening theclosed loop at signal Y box A and connecting the signal wire et with thefeed 6 and the signal-restoring wire 5 with the ground, as shown in thesimplified diagram Fig. 6, so that a signal-setting circuit isestablished which passes through both signal boxes. The current in saidcircuiti operates mechanism whiclr sets the signals at both ends of theblock.

The detail manner in which the signalsetting circuit is established isas follows: lVhen this circuit is completed even momentarily, the magnetl is energized thereby attracting the armature d and breaking theconnection between thecontacts 51, 52, and making the connection betweenthe contacts 49, 50. Simultaneously the signalsetting magnet a isenergized thereby attracting the armature 9 whereby the contacts 21, 22and 23, 24 aie bridged and simultaneously the arm 26 is swung backwardlyby the walls of the V-shaped notch 29 thereby breaking the connectionbetween the contacts 33, 34. As soon as the signal-setting magnet a hasbeen energized thereby to attract the armature 9, said armature becomeslocked in this position by the automatically-acting lock 36 as abovedescribed'. The bridging of the contacts 21, 22 and 23, 24 by theenergization of the magnet a operates to establi sh a filialsignal-setting circuit which leads l through signal box B so that themechanism at said box is set in operation to set the signal at the farend of the block. This nal signal-setting circuit is shown in thesimplified diagram view Fig. 6.

The circuit in detail is shown in the heavy lines Fig. 5 and is asfollows: From the feed wire through wires 70, 72 to the magnet a, thencethrough wire 73 to contact 21, thence to contact 22 and through wire 81to contact 57, from contact 58 to the signal wire 4 and to the contact58 of box B, through contacts 56, 57, wires 81, 87, signal-settingmagnet of box B, wire 870, contacts 34, 31, 33, wires 86, 83, coils ofthe lock-releasing magnet c, wire 82, contacts 52, 48, 51,signalrestoring wire 5, thence to contacts 49, 47, 50, and wire 91 tothe ground 7. Then the current is thus established the signal-settingmagnet at box B is energized, and the armature 9 at said box istherefore drawn over by said magnet and locked in such position and thecontacts 17 and 18 and 19 and 20 are bridged. This movement of thearmature 9 and the contacts carried thereby breaks the electricconnection between the signal-restoring wire 5 and the signal wire 4 atsignal box B and connects said signal wire 4 to the ground and to thesignal at said signal box, and thus completes the signal circuit andsets the signals.

The complete signal circuit is shown in the simplified diagram Fig; 8,and is also shown in heavy lines in Fig. 7. The first part of thiscircuit from signal box A to signal box B is exactly as shown in Fig.'5, and as above described the energizing' of the signal-setting magnet 5at box BV results in breaking the connections between the contacts 33,34 (thus disconnecting the signalrestoring circuit 5 from the signalcircuit 4) and establishing connections between the contacts 17, 18 sothat the current after passing through the magnet b takes the wire 88,contact 17, 13, 18 and wire 89 to the ground. The wire 89 has the redlight in it and constitutes a signal-containing circuit, and theoperation of the signal-setting' magnet ZJ connects thesignal-containing circuit with the signal circuit and then sets thedanger signal at the exit end of the block. The wire which alsoconstitutes a signal-containing circuit at the entering end of theblock, has already beenconnected to the signal circuit, -and when saidcircuit is complete a white light is exhibited at the entering end ofthe block and a red light at the opposite end of the block. Thiscondition will continue until the car leaves the block. lhen the cardoes thus leave the block, the signal system is restored to thecondition shown in Figs. 1 and 2 in which the signal circuit wire 4 andthe signal-restoring wire 5 are both disconnected from the signal andare connected at their ends to form the closed loop. This restoring ofthe signal to the normal condition is secured by completing a circuitthrough the signal-restoring wire and through both of the lock-releasingmagnets c whereby said magnets become energized and thus operate torelease the locks 36' whereby the armatures 9 are returned to theirneutral position, as seen in Fig. 1, the returning of the armatures tothis neutral position operating to restore the circuits to the conditionshown in Fig. 1. The first step in restoring the signal occurs when thecar leaving the block operates the track switch 80 at the exit end ofthe block. The closing of this switch establishes a preliminarysignal-restoring circuit such as shown in F ig. 9 which includes thewires 70, 78, magnet c, wire 79, and switch 80. `When this circuit isclosed the magnet e becomes energized and its armature e is attractedwhereby the contact 53 is caused to bridge the contacts 54, 55. Uien thecar passes cnto the siding 3a it operates the track switch 103 at thesiding which is connected with the magnet f by a wire 104, and theoperationv of this track switch results in closing the signal-restoringcircuit through the sigual-restoring wire 5 and the two lock-releasing'magnets c in the manner shown in heavy lines in Fig'. 10. The completesignal-restoring circuit thus formed is connected with the feed at twoplaces, one branch of said circuit passing through each of the magnetsc. The circuit which extends through the lock-releasing magnet c at thesignal box B comprises the wires 70, 72 and contacts 20, 19, wire 83,the coils of the lock-releasing magnet c, wire 82, contacts 52, 51, andthe signal wire 5, contacts 54, 53, 55, wire 105, magnet f, wire 104,and switch 103.

The circuit through the lock-releasing magnet c at signal box Acomprises the wire 70, 72, 85, contacts 24, 23, wire 84, lock-releasingmagnet c, wire 82, contacts 52, 51, and signal-restoring wire 5,contacts 54, 55 at signal box B, magnet f and wire 104. The twolock-releasing magnets c are thus in parallel and the current taken fromthe feed at two places passes through both of them, energizes them, andthus causes the locks 36 at each signal box to be released from theheads 37, thereby permitting the armatures 9 both to return to theirneutral position. The movement of said armatures into their neutral orcentral position breaks the connection between the signal circuit 4 andthe feed at signal box A and also breaks the connection between saidsignal circuit and the ground at signal box B. As soon as the armatures9 return to their normal position the contact 31 is again brought intoengagement with the contacts 33, 34 at each signal box and the circuits4 and 5 are thereby connected together at their ends again, thusrestoring the system to the condition shown in Figs. 1 and 2.

lith the embodiment herein shown it is necessary that the contact 53should remain bridging the contacts 54, 55 while the car is passing fromthe track switch 80 to the track switch 103 on the siding and thereforeI have provided an automatic locking device for holding the armature cin the position in which it is attracted by the magnet e. This lookingdevice is shown in Figs. 11 to 15, and comprises a pin 100 extendinglaterally from the armature c and a pivoted locking pawl 101 which isadaptedto engage automatically with the locking pin 100, as shown indotted lines Fig. 14, when the armature e is attracted. This lockingpawl acts to retain the armature c in its position with the contact 53bridging the contacts 54, 55 until said pawl is released when the magnetf is energized. The armature f of the magnet f has extending therefrom aprojection 106 which is adapted to engage an arm 107 rigid withthe pawl101 thereby to release said pawl from the pin 100 and permit thearmature c to resume its normal position under the influence of a springor other suitable mechanism. When the `magnet f is energized theattraction of its armature breaks the signal circuit between thecontacts 57, 58, and as stated above, the movement of the armatures 9into their normal position operates to connect the two ends of the wires4 and 5, thus forming the closed loop above described.

It will be noted that at the entering end of the block the track switch77 is slightly in advance of the track switch 30 so that the switch 77will be operated first. It is the switch 77 at the entering end of theblock that is utilized for establishing the preliminary signal-settingcircuit, and the switch 80 at the exit end of the block is used forsetting the preliminary signal-restoring circuit.

The interlocking connection between the arma-tures d and e is for thepurpose of preventing the armature c from being operated when the carpasses over the switch 80 at the entering end of the block so that whenthe car enters the block the proper circuit will always be establishedfor setting the signal.

At the leaving end of the block the track switch S0 is first operatedthereby to set the preliminary signal-restoring circuit and when thearmature e is energized the armature cl becomes locked so that thepassage of the car over the switch 77 does not affect the operation ofrestoring the signal.

The signal system herein shown is adapted to be operated by a carpassing in either direction. 1t will be noticed that both signal boxesare alike and that the track switches 77 and S0 at each.end of the blockare so arranged that in whichever direction the car is traveling thetrack switch 77 will be first operated at the entering end of the blockand the track switch S0 will be operated at the exit end of the block.At the turn-out between the blocks, there is a track switch 103 in thesiding connecting with the signal box at the end of the block from whichthe car has come, and a similar track switch 108 in the main lineopposite the siding connecting with the signal box at the end of theblock from which the car on the main line has just emerged, so that inwhichever direction a car is passing the signals in the block from whichthe car has just come will be restored.

It is not essential to my invention that the circuit connections shouldbe made by means of track switches as trolley switches might be readilysubstituted for the track switches. l/Vhere track switches are employedinstead of trolley switches, however, it is desirable to have the twodirection-controlling magnets (Z and e which are for the purpose ofcontrolling the direction of the current according to the direction inwhich the car isv passing, that is, whether passing into or out from theblock. A trolley switch, however, is usually constructed so that withinthe switch itself is means for controling the direction of the currentaccording to the direction that the car is moving and where trolleyswitches are employed, it is not necessary to use these magnets Z and cin the signal box.

Another feature of my invention to which I desire to call attention isthe fact that the signals 90 and 71 are in signal-containing circuitsseparate from the circuits connecting the two signal boxes. Theadvantage of this arrangement is that if by any accident the wires 4 and5 should become crossed with other wires when the signal system is isoin its normal condition, as shown in Fig. l, the signals Will not beoperated.

Vhile I have shown herein the preferred embodiment of my invention, yetit Will be obvious that the system as a system might be operated bymechanism diierent from What is shown, that is to say, the particulararrangement of magnets and contacts in the signal boxes is not essentialto the invention which resides broadly in making a signal system inwhichl the Wires connecting the signal boxes are in a closed loopdisconnected both from the feed and from the ground and in operating thesignal as herein described. It Will be obvious, therefore, that manychanges in the constructional details of the parts may be made Withoutin any Way departing from the invention expressed in the appendedclaims.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is l. A block signal system comprising anormally-closed circuit extending the length of the block anddisconnected from the source of electricity and from the ground, andmeans to establish a signaling circuit by opening said normally-closedcircuit and connecting one point thereof to the source of electricityand another point thereof to the ground.

2. A block signal system comprising a normally-closed circuit extendingthe length of the block and normally disconnected from both the sourceof electricity and fromthe ground, and means operated by a car enteringthe block to open said normally-closed circuit and connect one endthereof to the source of electricity and the other end thereof to theground.

3. A block signal system comprising a normally-closed loop extending thelength of the block and disconnected both from the source of electricityand from the ground, means operated by a car entering the block to opensaid loop and connect it at the entering end of the block with a sourceof electricity and at the opposite end of the block with the ground.

if. A block. signal system comprising a normally-closed loop extendingthe length of the block and disconnected both from the source ofelectricity and from the ground, and means operated by a car enteringeither end of the block to open said loop and connect it at the enteringend of the block with a source of electricity and at the opposite end ofthe block With the ground.

5. In a signal system, the combination With a normally-closed loopextending the length of the block, a signal-containing circuit at eachend of the block normally disconnected from the loop, and means to openthev loop and connect said signal-containing circuits thereto.

6. In a block signal system, the combina-v tion With a normally-closedloop extending the length of the block, means operated by a car enteringthe block to open said loop and connect it at the entering end of theblock both to a source of electricity and to a signal, and toi connectit at the opposite end ofthe block both to the ground and to a signal.

'7. In a block signal system, the combination With a normally-closedloop extending the length of the block and disconnected from both thesource of electricity and the ground, of a signal-containing circuit ateach end of the block, each being disconnected from said loop and onebeing connected to the source of electricity and the other to theground, and means to break the loop and connectit to saidsignal-containing circuits.

S. In a block signal system, the combination with a normally-closed loopextending the length of the block and disconnected from both the sourceof electricity and the y ground, of a signal-containing circuit at eachend of the block, each being disconnected from said loop and one beingconnected to the source of electricity and the other to the ground, andmeans operated by a car. entering the block to break the loop andconnect it to both of the signal-containing circuits.

9. In a block signal system, the combination with a normally-closed loopextending the length of the block and disconnected from both the sourceof electricity and the ground, of a signal-containing circuit at eachend of the block, each being disconnected from said loop and one beingconnected to the source of electricity and the other to the ground,means operated by a car entering the block to break the loop and connectit to both the signal-containing circuits, and means operated by a-carleaving the block to restore the loop and disconnect it from thesignalcontaining circuits.

l0. In a block signal system, the combination with a closed loopextending the length of the block, of two signal-containing circuits ateach end of the block, one circuit at each end being connected to thesource of electricity and at the other end to the ground and all of saidcircuits being disconnected from the loop, and means actuated by a carentering the block from either end to open the loop and connect it atsaid end to one of the signal-containing circuits and at the other endto an oppositely-disposed signalcontaining circuit.

l1. In a block signal system, the combination with a closed loopextending the length of the block, of tivo signal-containing circuits ateach end of the block, one circuit at each end being connected to thesource of electricity and at the other end to the ground and all of saidcircuits being disconnected from the loop, and means actuated by a carentering the block to open the loop and connect it at the entering endof the block with the signal-containing circuit connected with thesource of electricity and at the opposite end of the block with thesignal-containing circuit connected to the ground.

12. In a block signal system, the combination with a closed loopextending the length of the block, of two signal-containing circuits ateach end of the block, one circuit at each end being connected to thesource of electricity and at the other end to the ground and all of saidcircuits being' disconnected from the loop, means actuated by a carentering the block to open the loop and connect it at the entering endof the block with the signal-containing' circuit connected with thesource of electricity and at the opposite end of the block with thesignal-containing circuit connected to the ground, and means actuated bya car leaving the block to restore the loop and disconnect thesignalscontaining circuits therefrom.

13. In a block signal system, the combination with a closed loopextending the length of the block and disconnected from the source ofelectricity and from the ground, means to open said loop and connect itat one end of the block to the source of electricity and at the sametime connect it to the ground first at the same end of the block andthen at the opposite end thereof.

11. In a block signal system, the combination with a signal wire and asignal-restoring Wire extending the length of the block and normallyconnected at their ends to constitute a closed loop, of means operatedby a car entering the block to open said loop at both ends and connectone end of the signal Wire to the feed and the other end to the ground.

15. 1n a block signal system, the combinau tion with a signal wire and asignal-restoring Wire extending the length of the block and normallyelectrically connected at each end, of a signal-containing circuit atone end of the blook normally disconnected from the signal wire, andmeans operated by a car entering the opposite end of the block to breakthe connection between said two wires at both ends of the block andconnect the signal wire with the signal circuit and also with the feedand ground.

16. In a block signal system, the combination with a signal wire and asignal-restoring wire extending the length of the block and normallyelectrically connected at each end, of a signal-containing circuit atone end of the block normally connected with: the ground anddisconnected from the signal wire, of means operated by a car enteringthe opposite end of the block to brealr'the connection between the twowires at both ends of the block and to connect the signal wire at theentering end of the block with the feed and at the opposite end with thesignal-containing circuit.

17. In a block signal system, the combination with a signal wire and asignal-restoring wire extending the length of the block, of asignal-containing circuit at one end of the block normally connectedwith the ground and disconnected from the signal wire, means operated bya car entering the opposite end of the block to connect the signal wireat said end of the block with said feed and at the first-named end ofthe block with the signalcontaining circuit, and means operated by a carleaving the block to establish a circuit through the signal-restoringwire thereby to restore the signal.

ln testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

JOHN J. RUDDICK.

W'itnesses Louis C. SMITH, FREDERICK S. GREENLEAF.

